I've watched this talk a lot and it has really opened my eyes.
I'm currently suffering from HA and general stress from my personal life/exams/uni work/ existential crisis etc. I randomly found this and it has really changed my view on our stress response.
From what i know of panic attacks and anxiety, the stress response is a milder form of what we experience during a panic attack; it is our bodies natural and healthy response to the pressure put on us today. But what Kelly is saying here is that if we view stress and our bodies reaction to it as a POSITIVE thing, not only will it alter our brains but keep us healthy!!!
There are so many other talks on TED but this one has really struck a chord, so enjoy!